Swelling up fore skin. Plz help me.

Hello sir, I am a twenty year boy ...i usually mastrubate with my hands in my teenage(no issues of fore skin swelling that time) but when i am 20 i started mastrubating with prone position and completely discountinue mastrubation with normal hand.then i got to know that this type of mastrubating system effects my sexual life in future so decided to give up that prone style and started the natural hand mastrubation but suddenly i realised i have a issue with my ejaculation( although i am able to ejaculate after a long mastrubation session like 20 to 24 mins) and my fore skin was swelled up after each mastrubation...and the swelling ness also go down its own after a day ...so i am very afraid that i have a serious disease ..plz help me..